This sounds very much like our paper system, but we have 6 signatories based on roles not positions in the company

I think best practice is that you resist (if possible) as your Change manager (probably answerable to said director) should have final say after taking into account the Business requirements - In practice will your director have the time to sign of all the changes? - ours are far too busy.

It will probably be ok in the beginning with only a few changes per month, but as the process is used by more people, we have found that they were unavailable and we needed to find deputies more and more.

As I said we now have sign-off based on roles (we are a Managed Services provider)

Implementer, Customer Service manager for Client, Service Desk, Operations, Peer(for Technical content) and Change Team